Fan device

ABSTRACT

A fan device includes a fan frame and a fan blade wheel. The fan blade wheel is movably joined to the fan frame and has a hub with fan blades extending radially from the circumferential side of the hub. A guiding groove is provided at the circumferential side of the hub between any two of the fan blades. The guiding groove has a leading section, which is a smooth shallow recess corresponding to direction of fluid flow, and a guiding section, which extends from the leading section and provides a deep recess. When the fan blade wheel rotates, the fluid moves along the leading section and is sucked to the guiding section before moving outward. Hence, it decreases chance of the intake fluid becoming turbulence or random flow and increases the fluid flow to enhance effect of heat dissipation significantly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a fan device and particularly to a fan device, which has a hub capable of guiding fluid effectively.

2. Brief Description of the Related Art

Referring to FIGS. 1 and 2, the conventional fan includes a fan blade wheel 11 and a fan frame 12. The fan blade wheel 11 provides a hub 111 with a plurality of fan blades 112 extending radially from the circumferential side of the hub 111 as shown in FIG. 3. The fan frame 12 has four lateral side walls and an inner wall with an air inlet side 123 and an air outlet side 124. A fan blade wheel seat 121 is provided at the center of the air outlet side 124. The air outlet side 124 is mounted to a heat sink 13 with fasteners 226 passing through locating holes 125 at the four corners of the fan frame 12.

The hub of the conventional fan device does not provide a guiding flow part except fan blades 112 so that the fluid flow moves toward all directions after passing through a space between every two neighboring fan blades once the fluid moves into the fan blade wheel 11. As a result, fluid pressure of the fluid moving toward the outlet 124 due to resistance of the outer surface of the hub 111 and becomes getting lower due to resistance of the outer surface of the hub 111 and it is easy to result in reversed flow at low pressure area of the back of the hub 111 to affect heat dissipation.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a fan device in which a guiding groove is provided at the circumferential side of the hub of the fan blade wheel between every two neighboring fan blades to guide the fluid flow for decreasing turbulence of the intake flow and increasing fluid flow.

In order to achieve the preceding object, a fan device according to the present invention includes a fan wheel, which has a hub with a facial side, a circumferential side and an open side, and having a plurality of fan blades extending radially from the circumferential side, and a frame, which has a fluid outlet side and providing a fan wheel seat at the center of the air outlet side for movably fitting with the fan wheel; wherein the circumferential side has a plurality of guiding grooves and each of the guiding grooves is disposed between every two adjacent fan blades of the fan blade wheel.

BRIEF DESCRIPTION OF THE DRAWINGS

The detail structure, the applied principle, the function and the effectiveness of the present invention can be more fully understood with reference to the following description and accompanying drawings, in which:

FIG. 1 is an exploded perspective view of the conventional fan;

FIG. 2 is a perspective view of the conventional fan shown in FIG. 1;

FIG. 3 is a top view of the fan blade wheel in the conventional fan;

FIG. 4 is an exploded perspective view of a preferred embodiment of a fan device according to the present invention with a heat sink;

FIG. 5 is a perspective view of the fan device shown in FIG. 4 attached to the heat sink;

FIG. 6 is a top view of the fan blade wheel in the fan device according to the present invention;

FIG. 7 is a plan view of another type fan blade wheel;

FIG. 8 is a plan view of a further type fan blade wheel; and

FIG. 9 is a side view of a further type of fan blade wheel.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 4 and 5, a preferred embodiment of the fan device according to the present invention includes a fan blade wheel 21 and a fan frame 22. The fan frame 22 has four lateral side walls with a plurality of air apertures (not shown) and an inner wall with a fluid inlet side 223 and a fluid outlet side 224. A fan blade wheel seat 221 is provided at the center of the fluid outlet side 224. The fluid outlet side 224 is mounted to a heat sink 23 with fasteners 226 passing through locating holes 225 at the four corners of the fan frame 22.

The fan blade wheel 21 has a hub 211 with a plurality of fan blades 212 extending radially from a circumferential side 2112 of the hub 211. The hub 211 further has circular facial side 2111 perpendicular to the circumferential side 2112 and an open side opposite to the facial side 2111 such that a motor stator and rotor (not shown) are capable of receiving in the hub 211. A shaft (not shown) is joined to the inner side of the facial side 2111 and movably fits with an axial barrel 227 disposed at and extending from the center of the fan wheel seat 221. Further, a plurality of guiding grooves 213 are provided at the circumferential side 2112 of the hub 211 next to the fan blades 212.

Referring to FIG. 6 in company with FIG. 4, each of the guiding grooves 213 is disposed on the circumferential side 2112 in a way of being between any two adjacent fan blades 212 and extending from the edge of the facial side 2111 to the open side. In addition, the respective guiding groove 213 has a leading section 2131 and a guiding section 2132. The leading section 2131 extends corresponding to the fluid flow direction to form a shallow recess and the guiding section 2132 extends from the leading section and constituting a deep recess at the circumferential side 2112 of the hub 211.

When the fan wheel rotates, fluid near the hub 211 as the dash lines shown in FIG. 6 is sucked into the guiding groves 213 along the leading section 2131 and then moves to the guiding section 2132 before flowing outward toward the heat sink 23 at the fluid outlet side 224 as shown in FIG. 4. In this way, intake fluid near the hub 211 is incapable of becoming turbulence or a random flow so as to increase fluid passing a space between every two neighboring fan blades 212. Furthermore, the fluid flow can move outward the fan directly to prevent from decreasing fluid pressure so as to increase effect of heat dissipation.

The preceding embodiment is illustrated with the fan blade wheel rotates clockwise. In case of the fan blade wheel rotates counterclockwise as shown in FIG. 7, the same performance can be reached as well.

Referring to FIGS. 8 and 9, the facial side 3111 of the hub 211 projects outward with an approximate cone shape and the guiding grooves 213 extending from the open side of the hub 211 to the tip of the facial side 3111. In this way, the preceding advantages of the invention also can be obtained.

While the invention has been described with referencing to preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims. 

1. A fan device comprising: a fan wheel having a hub with a facial side, a circumferential side and an open side, and having a plurality of fan blades extending radially from the circumferential side; a frame having an air outlet side and providing a fan wheel seat at the center of the air outlet side for movably fitting with the fan wheel; wherein the circumferential side has a plurality of guiding grooves and each of the guiding grooves is disposed between every two adjacent fan blades of the fan blade wheel.
 2. The fan device as defined in claim 1, wherein the fan wheel seat is joined to an inner wall of the frame with a plurality of rib bars.
 3. The fan device as defined in claim 1, wherein the respective guiding groove further comprises: a leading section being disposed corresponding to direction of fluid flowing and extending along the circumferential side to constitute a smooth shallow recess; and a guiding section extending from the leading section and extending inward the circumferential side to form a deep recess.
 4. The fan device as defined in claim 1, wherein the respective guiding groove extends from the facial side to the open side.
 5. The fan device as defined in claim 1, wherein the facial side has a flat surface.
 6. The fan device as defined in claim 1, wherein the facial side has a shape similar to a cone.
 7. The fan device as defined in claim 6, the guiding grooves extend to the tip of the facial side from the open side. 